After the American 911 events, more and more attention is paid to security inspection in the aviation field. The CT technology-based security inspection products have incomparable advancements and obviously advantageous performance indices. The American Transportation Standardization Agency (TSA) considers that CT devices and detection methods thereof are important ways to implement security inspection at the airport. Common machines for goods, i.e., X-ray machines, achieve perspective imaging to obtain sharp DR images, which have formed fixed impression in the users' minds. Users have been familiar with the DR images. In a DR system, the X-ray source and detectors are fixed and irrotational. These DR images are generally images in the top angle of view or images in the bottom angle of view, which are very intuition and convenience for view. Rich experience formed from image reading and image recognition is based on these intuitional DR images. An excellent image recognizer needs to view more than several tens of thousands of actual DR images. A person generally needs to work more than 90 workdays to become an excellent image recognizer. Currently, there are numerous excellent image recognizers working in industries such as healthcare, security inspection or the like. When there is no DR image, these experienced image recognizers cannot correctly implement image recognition.
Although some existing CT systems have ready-made three-dimensional data, there is no DR image. The image recognizer may feel unaccustomed when he/she suddenly views the three-dimensional image. For example, due to an unsuitable angle of view, prohibited goods (for example, guns) may be a small agglomeration in the three-dimensional image and the pattern thereof is unclear. When the image recognizer suddenly views the three-dimensional image, he/she does not know why the guns suddenly become a small agglomeration. When the image recognizer views the three-dimensional image individually, he/she still does not know what is carried by a passenger. Therefore, even if there is a three-dimensional image, the image recognizer still wants to compare the three-dimensional image with the familiar DR image and use the existing rich experience in image recognition of the DR image. That is, the image recognizer wants to obtain such an arrangement that a display is placed on the left to display a DR image and a display is placed on the right to display a CT image. With the existing experience in image recognition of a DR image, numerous image recognizers can more rapidly, more conveniently, and more accurately know what is carried by a passenger. Thus, lots of manpower and time can be saved.
In addition, with respect to a CT device having a DR system, if a user selects a particular position, it needs to implement DR-CT registration to display a slice in the particular position. It can be known whether the particular position is on a head portion, a middle portion, or a tail portion of a luggage based on belt encoding of a hardware apparatus. However, as the belt encoding is missing or absent or cannot achieve matching in the transportation process, the method cannot accurately implement registration. There is a need for a novel and effective registration method.